Prospection and production of oil fields in deep water is accompanied by complex underwater operations. Oil production, in general, requires installation and retrieval or maintenance of equipment that is settled on the seabed. In these operations, installation of the equipment is carried out by vessels or floating structures equipped with a rig for handling drill pipes. These are referred as drilling rigs and completion rigs. They are very stable when encountering heave waves but have high daily operation costs.
In deep waters, underwater operations require the use of these vessels for a longer period of time. Thus, development of systems and methods that minimize the use of these vessels is of fundamental relevance to oil production from oil fields in deep water.
For example, U.S. Pat. No. 6,752,100 teaches devices and methods for installation of underwater equipment via vessels without drill pipes. However, these devices are limited to equipment provided at a compact scale and size, such as, for example, WCT—Wet Christmas Trees and production bases.
An example of subsea equipment hereinafter referred to as a subsea module of great length may be found in patent application PI 0400926-6, which issued as U.S. Pat. No. 7,314,084, and U.S. Pat. No. 4,900,433. A subsea module is basically a thin tube of long length, i.e., a dozen meters, that usually has to be retrieved for maintenance of a motor/pump assembly coupled to it. Due to its length, retrieving the module to the surface, fixing the assembly and replacing it are complex operations that take a long time (e.g., many days) and usually require the use of an offshore rig, with a high daily cost.
Therefore, ways to minimize or eliminate the complexity during installation and replacement of equipment of great length, such as subsea modules, via vessel and cable operations, without the need of using rig and drill pipes, are still being sought.